Study of the toxic effect and safety of vitamin E supplement in male albino rats after 30 days of repeated treatment

Assessment of the protective effect of vitamin E supplementation on oxidative damage of diabetic rat spleen induced by streptozotocin

AIMS

Increased oxidative stress in diabetes mellitus may lead to splenic damage, contributing to decreased immunity. This study aims to evaluate the potential of vitamin E supplements as a protective agent against spleen injury by examining physiological, hematological, biochemical, and histological changes in diabetic rat model.

METHODS

Diabetes was induced in male wistar albino rats through an intraperitoneal injection of 50 mg/kg Streptozotocin, and the rats were randomly divided into five groups. The rats were then administered varying doses of vitamin E for 14 consecutive days. Assessments included renal function tests, blood glucose levels, complete blood counts, lipid profiles, tissue oxidative stress and spleen histology. An acute toxicity study was also conducted on normal rats.

RESULTS

Vitamin E supplementation did not result in any mortality up to 5000 mg/kg body weight. The treated diabetic group showed improved metabolic characteristics, such as normal body weight, food and water intake and a reduced spleen index compared to the untreated diabetic group. Significant improvements were observed in hematological parameters like packed cell volume (PCV), hemoglobin concentration, RBC (red blood cells) and WBC (white blood cells) counts. HCA (Hierarchical Cluster Analysis) of these parameters indicated that doses of 100 mg/kg and 150 mg/kg were most similar to normal condition. Catalase and MDA (Malondialdehyde) assays showed a substantial reduction in oxidative stress in spleen tissue and histopathological examination revealed significant regenerative effects.

CONCLUSION

This study demonstrated that vitamin E supplementation significantly enhanced various metabolic, hematological, biochemical, and histological parameters in the diabetic group compared to those who did not receive the treatment. Among the doses tested, 100 mg/kg and 150 mg/kg body weight were found to yield the most favorable outcomes.

The potential ameliorating effect of vitamin E on bleomycin - induced lung fibrosis in adult albino rats

Lung fibrosis is a critical interstitial lung disease with poor prognosis. There is an urgent need to develop a proper and cost-effective therapeutic modality that can reverse and/or ameliorate lung fibrosis. Vitamin E is one of the widely investigated dietary antioxidants which has been linked to improvement of many health problems. The current study was conducted to evaluate the possible roles of vitamin E in prevention and treatment of bleomycin (BLM) induced lung fibrosis. Physiological, anatomical, histopathological and immunohistochemical studies were done to assess and compare between the structure and function of the lung tissue in lung fibrosis model, early and late treated groups with vitamin E. Furthermore, measurement of transforming growth factor-β(TGF-β), E-cadherin, Smad-3, BAX, BCL2, malondialdehyde (MDA), and superoxide dismutase (SOD) were done. The study revealed that administration of vitamin E helped to improve signs of lung fibrosis, as reflected by amelioration of structure and functions of lungs as well as the decrease in TGF-β levels and inhibition of α-SMA/collagen I profibrotic pathway. These findings highlight the importance of administration of vitamin E as a prophylactic agent prior to BLM therapy and as an adjuvant treatment in cases of lung fibrosis.

Antioxidant therapy for hepatic diseases: a double-edged sword

Liver diseases are complex conditions, significantly influenced by oxidative stress. This comprehensive review assesses the therapeutic role of antioxidants like l-ascorbic acid and α tocopherol, beta-carotene, various minerals, and plant-based ingredients in mitigating oxidative stress-induced liver diseases. The manuscript delves into the critical influence of genetic and epigenetic factors on disease susceptibility, progression, and response to antioxidant therapy. While animal studies suggest antioxidant efficacy in liver disease treatment, human trials remain inconclusive, and caution is advised due to its possible potential pro-oxidant effects. Moreover, the interactions of antioxidants with other drugs necessitate careful consideration in the management of polypharmacy in liver disease patients. The review underscores the need for further research to establish the clinical benefits of antioxidants with understanding of possible antioxidant toxicities to elucidate the intricate interplay of genetic, epigenetic, and environmental factors in liver diseases. The aim is to foster a better understanding of the knowledge on hepatic disease management with judicial antioxidant therapies.

α-Tocopherol Ameliorates Redox Equilibrium Disorders and Reduces Inflammatory Response Caused by Diclofenac-Induced Nephrotoxicity in Male Wistar Rats

Background Diclofenac (DCF), a nonsteroidal anti-inflammatory drug (NSAID), is widely used for its analgesic and anti-inflammatory properties, but it can also be nephrotoxic. Vitamin E (α-tocopherol) has been shown to protect against renal toxicity caused by various agents, including NSAIDs. This study aims to evaluate the pathophysiology of renal damage and the nephroprotective effect of vitamin E against DCF-induced renal damage in male Wistar rats. Animal and methods Twenty-four male Wistar rats, divided into six equal groups, were used for the study. Group 1 (control group) was treated with distilled water only, while the other groups received either high or low doses of DCF with or without a fixed dose of vitamin E. Renal function was assessed by measuring serum urea, creatinine, and kidney injury molecule-1 (KIM-1). Oxidative damage and renal antioxidant levels were also assessed. Additionally, the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), renal cytokine tumor necrosis factor-α (TNF-α), and histopathological changes were evaluated. Results DCF caused a significant increase in serum urea, creatinine, KIM-1, TNF-α, NF-κB, and malondialdehyde levels compared to the control group. However, in the groups treated with DCF plus vitamin E, a significant reduction (P<0.05) in the levels of pro-inflammatory cytokines and malondialdehyde was observed, along with improvement in renal function indices, superoxide dismutase, catalase, and glutathione peroxidase levels comparable to the control group. The observed renal histopathological changes were consistent with the results of the biochemical parameters between the treated groups and the normal control rats. Conclusion Findings from this investigation suggested that DCF can be nephrotoxic at a certain dose when used for a prolonged duration. Co-administration of vitamin E suppressed the elevated inflammatory cytokines and led to changes in the cell redox-sensitive signaling pathways induced by DCF, with eventual amelioration of the nephrotoxicity.

Vitamin E (α-Tocopherol) Does Not Ameliorate the Toxic Effect of Bisphenol S on the Metabolic Analytes and Pancreas Histoarchitecture of Diabetic Rats

This study investigated whether the coadministration of vitamin E (VitE) diminishes the harmful effects provoked by plasticizer bisphenol S (BPS) in the serum metabolites related to hepatic and renal metabolism, as well as the endocrine pancreatic function in diabetic male Wistar rats. Rats were divided into five groups (n = 5-6); the first group was healthy rats (Ctrl group). The other four groups were diabetic rats induced with 45 mg/kg bw of streptozotocin: Ctrl-D (diabetic control); VitE-D (100 mg/kg bw/d of VitE); BPS-D (100 mg/kg bw/d of BPS); The animals from the VitE + BPS-D group were administered 100 mg/kg bw/d of VitE + 100 mg/kg bw/d of BPS. All compounds were administered orally for 30 days. Body weight, biochemical assays, urinalysis, glucose tolerance test, pancreas histopathology, proximate chemical analysis in feces, and the activity of antioxidants in rat serum were assessed. The coadministration of VitE + BPS produced weight losses, increases in 14 serum analytes, and degeneration in the pancreas. Therefore, the VitE + BPS coadministration did not have a protective effect versus the harmful impact of BPS or the diabetic metabolic state; on the contrary, it partially aggravated the damage produced by the BPS. VitE is likely to have an additive effect on the toxicity of BPS.

Evaluation of the Effect of Vitamin E on Reproductive Parameters in Morphine-Treated Male Mice

Background

Morphine is a narcotic pain reliever that is prescribed to reduce postoperative pain and can produce reactive oxygen species (ROS). Therefore, it can have negative effects on spermatogenesis and male fertility. Vitamin E is an effective antioxidant which plays an important role in membrane lipid peroxidation due to increased ROS. The present study aimed to evaluate the effects of vitamin E and morphine on sperm parameters, level of malondialdehyde (MDA), and diameter of seminiferous tubules in morphine-treated mice.

Methods

In this experimental study, 80 mice were divided into ten groups (n=8) including control, normal saline, vehicle, morphine, various doses of vitamin E (100, 200, 300 mg/kg), and morphine plus vitamin E (100, 200, 300 mg/kg) groups. The groups were followed up for 30 consecutive days. Sperm parameters, testis weight, the diameter of seminiferous tubules, and the level of MDA were analyzed and compared.

Findings

Data analysis showed seminal parameters decreased significantly (excluding sperm count) and there was an increase in the level of MDA in morphine-treated mice compared with the normal saline group (P<0.05). Administration of E100 to morphinetreated mice did not show a significant difference in the evaluated parameters compared with the morphine group. However, E200 and E300 significantly reduced MDA and improved sperm parameters (P≤0.05).

Conclusion

The results showed co-administration of vitamin E in high doses (200 & 300) could prevent the deleterious effects of morphine on some reproductive parameters and decrease the level of MDA in morphine-treated mice.

Vitamin E in the management of pancreatic cancer: A scoping review

Pancreatic cancer is the leading cause of cancer mortality worldwide. Research investigating effective management strategies for pancreatic cancer is ongoing. Vitamin E, consisting of both tocopherol and tocotrienol, has demonstrated debatable effects on pancreatic cancer cells. Therefore, this scoping review aims to summarize the effects of vitamin E on pancreatic cancer. In October 2022, a literature search was conducted using PubMed and Scopus since their inception. Original studies on the effects of vitamin E on pancreatic cancer, including cell cultures, animal models and human clinical trials, were considered for this review. The literature search found 75 articles on this topic, but only 24 articles met the inclusion criteria. The available evidence showed that vitamin E modulated proliferation, cell death, angiogenesis, metastasis and inflammation in pancreatic cancer cells. However, the safety and bioavailability concerns remain to be answered with more extensive preclinical and clinical studies. More in-depth analysis is necessary to investigate further the role of vitamin E in the management of pancreatic cancers.

Beneficial and adverse effects of vitamin E on the kidney

This article reviews the beneficial and adverse effects of high-dose vitamin E supplementation on the vitamin E status and renal function in human and rodent studies. The high doses of vitamin E, which can cause renal effects, were compared to upper limits of toxicity (UL) as established by various authorities worldwide. In recent mice studies with higher doses of vitamin E, several biomarkers of tissue toxicity and inflammation were found to be significantly elevated. In these biomarker studies, the severity of inflammation and the increased levels of the biomarkers are discussed together with the need to re-evaluate ULs, given the toxic effects of vitamin E on the kidney and emphasizing oxidative stress and inflammation. The controversy in the literature about vitamin E effects on the kidney is mainly caused by the dose-effects relations that do not give a clear view, neither in human nor animals studies. In addition, more recent studies on rodents with new biomarkers of oxidative stress and inflammation give new insights into possible mechanisms. In this review, the controversy is shown and an advice given on the vitamin E supplementation for renal health.

E, K, B5, B6, and B9 vitamins and their specific immunological effects evaluated by flow cytometry

It has been proven that vitamins play an essential role in preventing certain diseases since ancient times. It is thus fruitless to approach the roles of vitamins without making reference to the techniques used in evaluating the effects of these micronutrients. Therefore, the aim of this paper was to summarize the immunological effects of E, K, B5, B6, and B9 vitamins evaluated by flow cytometry. Some of these significant effects were presented and discussed: (a) The role of vitamins E in the prevention and treatment of different types of cancer. (b) The properties of K vitamins in the development and maintenance of pheochromocytoma Cell Line 12 (PC12) cells in Parkinson's disease; (c) The improvement effect of vitamin B5 on the loss of bone mass in low estrogen conditions; (d) The anticancer role of vitamins B6. (e) The role of Vitamin B9 in the regulation of Treg cells. As such, the flow cytometry technique used to assess these properties is essential to evaluate the immunomodulatory effects of certain vitamins. The technique undergoes constant improvement which makes it possible to determine several parameters with a role in the modulation of the immune function and at the same time increase the accuracy of the methods that highlight them.

Assessment of changes in the liver of pregnant female rats and their fetuses following monosodium glutamate administration

Monosodium glutamate (MSG) is a common flavor enhancer and stabilizer for ready-made or packaged foods. This research investigated the impact of MSG on the maternal and fetal liver. The present study was carried out on sixteen mature female Albino rats and eight male rats of reproductive age. The control group was dissected on day 20 of gestation. MSG group was administrated MSG daily at a dosage of 1 g/5 mL/kg body weight from day 0 to day 20 of gestation. The liver function and lipid profile of the control and treated mothers were investigated in the blood sera. The levels of nitric oxide (NO), tumor necrosis factor (TNF-α), superoxide dismutase (SOD), and reduced glutathione (GSH) activities in the liver homogenate of maternal and fetal tissue were assayed, in addition to histopathological, histochemical and immunohistochemical studies were done to the liver tissue. The activities of liver functions and lipid profile significantly altered in the treated mothers with MSG. MSG significantly reduced the SOD and reduced GSH activities in addition to the elevated TNF-α and NO in liver tissue of pregnant mothers and their fetuses. Severe histopathological alterations were observed in both maternal and fetal liver tissues of MSG-treated groups. Moreover, histochemical observations showed a reduction of total polysaccharides in the liver of pregnant rats and fetuses. A significant increase in the percentage area of positive immunoreaction for caspase 3 was observed in the liver of treated rats with MSG compared to the liver of the control. The liver of fetuses treated with MSG revealed an alteration like their mother. This study showed that during the gestational period MSG exposure resulted in several biochemical, histological, and histochemical changes in the maternal and fetal liver tissues which emphasize the toxic effect of MSG.

Evaluation of the neuroprotective effects of Vitamin E on the rat substantia nigra neural cells exposed to electromagnetic field: An ultrastructural study

Electromagnetic fields (EMFs) could induce oxidative stress (OS) in human tissues. Lipid peroxidation (LPO) is the main hallmark of OS that harms neural cell components, primarily lipids in the myelin sheaths and membranes. Vitamin E is a lipophilic antioxidant that protects cells from OS-related damages and inhibits the LPO process. In this study, male rats were assigned into three groups of Control, EMF, and EMF+ Vitamin E. The EMF producer equipment produced an alternate current of 50 Hz, 3 Mili Tesla (mT). At the end of the experiment, half of the substantia nigra in every sample was used for measurement of the malondialdehyde (MDA) level as the end-product of the LPO and activity of superoxide dismutase (SOD) enzyme. The next half of the tissue was prepared for transmission electron microscopy (TEM). In the EMF group, MDA level was enhanced and SOD value decreased significantly compared to the control group, but Vitamin E could restore these changes. In rats undergone EMF, heterochromatic nucleus and destruction in some portions of the nuclear membrane were detected. The segmental separation or destruction of myelin sheath lamellae was observed in nerve fibers. In treated animals, the nucleus was round, less heterochromatic, with a regular membrane. Separation of myelin sheath lamellae in some nerve fibers was slighter than the radiation group. Considering the results, EMF exposure induces LPO and triggers ultrastructural changes in the cell membranes, nucleus, and myelin sheath of substantia nigra cells, but Vitamin E consumption weakens these neuropathological alterations.

Copper oxychloride-induced testicular damage of adult albino rats and the possible role of curcumin in healing the damage

The current research study investigated the effect of 80 mg/kg b.wt./day curcumin (cur) against 50, 100, and 200 mg/kg copper oxychloride (COC) for 90 days induced testicular damage using histological, ultrastructural, and biochemical techniques. Histological and cellular abnormalities have been noted in seminiferous tubules of COC-treated group and treated group with Cur- and COC-treated group. The biochemical result showed that serum testosterone was significantly decreased in COC-treated rats and Cur COC-treated rats compared with the control groups. Testes copper content and malondialdehyde was increased, whereas the testes total antioxidant, manganese, ferrous, and zinc levels were decreased (p ≥ 0.05) compared to the control groups. In conclusion, the present work reported that the treatment of rats with 80 mg/kg body weight curcumin prior to treatment with COC did not mitigate the deleterious effects of COC and manifested no signs of protection.